Process of producing transparent, hard, insoluble, and infusible products of condensation from phenols and aldehydes



Patented Apr. 23, 1929. I

UNITED STATES PATENT OFFICE. I

LEONHARD UEUTSCH AND ISAK THORN, OF VIENNA, AUSTRIA, ASSIGNORB TO THE SELDEN COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OI DELA- WARE.

PROCESS OF PRODUCING TRANSPARENT, HARD, INSOLUBLE, AND INFUSIBLE PBOD- UCTS F CONDENSATION FROM PHENOLS AND ALDEHYDES.

Ho Drawing. Application filed September 15, 1928, SerialNo. 662,998, and. in Yugoslavia September 28, 1822i It is well known that the condensation of phenols and aldehydes into hard, insoluble and infusible products is carried out gradually and by degrees or steps. The solvent power of the condensation product is diminished in accordance with 1ts increasing insolubility, so that foreign matters, particularly water, which during the individual stages of the reaction are in solution, will be separated in a condition causing turbidity during the progress of the condensation reaction. Also products which are quite free from water contain such matters in a turbid state after having become solid. This is caused by the fact that the conversion is not large enough durin can stage of reaction, not even if employing arger quantities of the condensing agents (alkalies or acids). Thus the product of reaction always contains so a considerable part of the original components in a free state or at least in a state which is still capable of reaction, and also during the later stages of condensation the reaction will still be accompanied by a separation of Water.

-Hovvever such subsequent reactions may be avoided or reduced in case one of the two components is present in excess, but it is not desirable that an unaltered or unchanged original component be resent in the final product. in View of this the reaction prod not has to be freed irom the original components which are still capable of reaction before distilling oil" the Water, by a careful as washing-out or extraction. in this manner transparent and hard products are obtained, and at present such methcols'are generally used.

However such processes are expensive and lo troublesome, and the yields therefromare small, because a considerable part of the soluble condensation product is removed from the reaction product with the unchanged original components. Therefore the experiment has been made to avoid the methods of cleaning by adding hygroscopic substances to the product after the water has been distilled ed in order to bind the water of reaction produced during the hardening. Trans- 5o parent products may be obtained in this manner, but hitherto such methods have not been found satisfactory owing to undesirable secondary actions. There are two groups of admixtures acting in this manner, to the one.

group belong organic solvents, particularly alcohols, and to the other grou caustic alkalics and alkali carbonates. A adding the quantities of or anic solvents which are necessary for combining water, the mechanical properties 0 acts, namely hardness and solidity will suffer, while the alkalis cause a considerable darkening of the products in a veryshort time. 1

The characteristic feature of the present invention consists in the employment of a group of new hygroscopic substances, comprising the alkali salts of the aromatic earoxylic acids, which compared with the known groups possess none of the drawbacks of the latter. Such additions are even capable of binding far greater quantities of water than those separated during the subse' quent reaction, and even components which are insoluble in water or 1n the condensation product such as cyclic carbohydrates, monoowever when V with the the prod-v valent or pol -valent alcohols, abietic acid,

resin and so orth, result'in solid, trans arent solutions with the condensation pro not it these salts and their derivatives are present. The products obtained in this simple manner, whether with such additional components or without them, are of the same mechanical pro erties and fast colors as those cleaned by was ing or the like.

iln carrying out the invention the condensation either is erform'ed with small quantities of caustic allralies or their carbonates and thereafter the suitable quantities of these alkaline salts are added, or in order to accelcrate the condensation larger quantities of alkalies are employed and, subsequently they are transformed to those salts by the aromatic carbonic acids. the color-fastness of the final product it is of advantage to make use of a surplus of the carbonic acids. Y

Ex mple 1.

1 kilogram of phenol and 1 kilogram of for maldehyde, say in the form of a 40% solution, are brought to reaction with 2 grammes of In order to increase sodium carbonate, subsequently 50 grammes of sodium benzoate and 50 grammes of sodi- '11m salicylate are added, new the water is expelled; however it is not necessary to expel the whole of the water, and finally the residue of distillation is hardened in known manner.

1 kilogram of phenol and 1 kilogram of formaldehyde of 40% are condensed with 20 to 40 grammes of sodium carbonate, subseldquently 60 to 120 grammes of benzoic acid are added, and finally the Water is expelled and hardened as above described.

We claim:

1. A process of producing transparent, hard infusible condensation products which comprises subjecting phenols and aldehydes, capable of forming resins which can be hardened by heat, to condensation in the presence of a non-volatile alkali, volatilizing free we- 4. A process of producing transparent,

hard, infusible condensation products, which comprises subjecting phenols and aldehydes capable of forming resins, which can be hardened by heat, to condensation in the presence of a non-Volatile alkali, volatilizing free Water formed, adding to the product a COHI- pound containing a benzoic acid radical and then hardening the product by heat.

5. A process of producing transparent, hard, infusible condensation products, which comprises subjecting phenols and aldehydes capable of forming resins, which can be hardened by heat, to condensation in the presence of an alkali, volatilizing free Water formed, adding to the product an alkali metal benzoate and then hardening the product by heat.

in testimony whereof We affix our signa' tures.

DR. LEONHARD DEUTSCH. Inc. ilSAK THURN. 

